[STAINLESS STEEL TUMBLER]: Durable Steel Coffee Tumbler is firm, Rustproof, without metallic taste. The outer layer is powder coated, keeping the tumbler dry. [VACUUM SEALED TUMBLER]: Our 20oz Sealed tumblers has vacuum sealed lid that ensures a good insulation and leak proof. No matter which seasons you are in, you can enjoy your favorite hot and cold drinks for a long time.